Ageing and immunity: addressing immune senescence to ensure healthy ageing.

Among the greatest achievements of the 20th century, prolongation of life expectancy has been the result of improved health conditions, decreased childhood mortality, lower incidence of infectious diseases. The consequence is the rapid ageing of the world population, with the elderly representing over 25% of the entire population by the year 2030, of which 75% living in less developed countries. Ageing thus represents one of the major public health challenges of the 21st century.

Current issues in adolescent immunization.

Based on the December 2006 Fondation Mérieux International Scientific Symposium, the current state of adolescent immunization is reviewed with a focus on the policy and programmatic issues that impact the acceptability, initiation, and successful implementation. Key questions are identified with proposed strategies to help achieve successful adolescent immunization programs. The role of current vaccines targeted to adolescents, such as those directed against invasive meningitis, pertussis, and the human papillomavirus, is reviewed as well as their role in rejuvenating interest in adolescent immunization, and more importantly, adolescent health as a whole.

Ethical issues in medical research in the developing world: a report on a meeting organised by Fondation Mérieux.

This paper reports on a multidisciplinary meeting held to discuss ethical issues in medical research in the developing world. Many studies, including clinical trials, are conducted in developing countries with a high burden of disease. Conditions under which this research is conducted vary because of differences in culture, public health, political, legal and social contexts specific to these countries.

Implementation of good clinical practice guidelines in vaccine trials in developing countries.

The practicalities when applying the ICH GCPs (International Conference on Harmonization 1996 Good Clinical Practices [EU, MHLW, FDA. International Conference on Harmonization Guideline for Good Clinical Practice; 1997] in less developed countries (ldcs) are seldom discussed and we found no guidelines as how to "adapt" them. Below we illustrate how ICH GCP principles can be implemented in different settings.

The feasibility of a school-based VI polysaccharide vaccine mass immunization campaign in Hue City, central Vietnam: streamlining a typhoid fever preventive strategy.

We report the coverage, safety, and logistics of a school-based typhoid fever immunization campaign that took place in Hue City, central Vietnam; a typhoid fever endemic area. A cluster-randomized evaluation-blinded controlled trial was designed where 68 schools (cluster) were randomly allocated the single dose Vi polysaccharide vaccine (Typherix) or the active control hepatitis A vaccine (Havrix). A safety surveillance system was implemented.

Introducing Vi polysaccharide typhoid fever vaccine to primary school children in North Jakarta, Indonesia, via an existent school-based vaccination platform.

Objectives: To report results on coverage, safety and logistics of a large-scale, school-based Vi polysaccharide immunization campaign in North Jakarta.

Methods: Of 443 primary schools in North Jakarta, Indonesia, 18 public schools were randomly selected for this study. Exclusion criteria were fever 37.

Lessons and implications from a mass immunization campaign in squatter settlements of Karachi, Pakistan: an experience from a cluster-randomized double-blinded vaccine trial [NCT00125047].

Objective: To determine the safety and logistic feasibility of a mass immunization strategy outside the local immunization program in the pediatric population of urban squatter settlements in Karachi, Pakistan.

Methods: A cluster-randomized double blind preventive trial was launched in August 2003 in 60 geographic clusters covering 21,059 children ages 2 to 16 years. After consent was obtained from parents or guardians, eligible children were immunized parenterally at vaccination posts in each cluster with Vi polysaccharide or hepatitis A vaccine.

Epidemiological profile and burden of rotavirus diarrhea in Vietnam: 5 years of sentinel hospital surveillance, 1998-2003.

For 5 years, we have conducted sentinel surveillance for rotavirus at 6 hospitals in 4 cities in Vietnam. Stool samples obtained from >10,000 children <5 years old who were admitted to the hospital with diarrhea have been screened for rotavirus. Overall, 55% of samples were positive, and there was little variability in rates of detection of rotavirus between sites (44%-62%).

A mass vaccination campaign targeting adults and children to prevent typhoid fever in Hechi; expanding the use of Vi polysaccharide vaccine in southeast China: a cluster-randomized trial.

Background: One of the goals of this study was to learn the coverage, safety and logistics of a mass vaccination campaign against typhoid fever in children and adults using locally produced typhoid Vi polysaccharide (PS) and group A meningococcal PS vaccines in southern China.

Methods: The vaccination campaign targeted 118,588 persons in Hechi, Guangxi Province, aged between 5 to 60 years, in 2003. The study area was divided into 107 geographic clusters, which were randomly allocated to receive one of the single-dose parenteral vaccines.

The role of epidemiology in the introduction of vi polysaccharide typhoid fever vaccines in Asia.

Despite the availability of at least two licensed typhoid fever vaccines--injectable sub-unit Vi polysaccharide vaccine and live, oral Ty21a vaccine--for the last decade, these vaccines have not been widely introduced in public-health programmes in countries endemic for typhoid fever. The goal of the multidisciplinary DOMI (Diseases of the Most Impoverished) typhoid fever programme is to generate policy-relevant data to support public decision-making regarding the introduction of Vi polysaccharide typhoid fever immunization programmes in China, Viet Nam, Pakistan, India, Bangladesh, and Indonesia. Through epidemiological studies, the DOMI Programme is generating these data and is offering a model for the accelerated, rational introduction of new vaccines into health programmes in low-income countries.

Clinical case definition for the diagnosis of acute intussusception.

Objective: Because of the reported association between intussusception and a rotavirus vaccine, future clinical trials of rotavirus vaccines will need to include intussusception surveillance in the evaluation of vaccine safety. The aim of this study is to develop and validate a clinical case definition for the diagnosis of acute intussusception.

Methods: A clinical case definition for the diagnosis of acute intussusception was developed by analysis of an extensive literature review that defined the clinical presentation of intussusception in 70 developed and developing countries.

[Rotavirus surveillance data from Kunming Children's Hospital, 1998 - 2001].

Objective: To study the epidemiological status on rotavirus diarrhea in Kunming to improve the rotavirus vaccine immunization program.

Methods: A hospital-based sentinel surveillance program for rotavirus was set up among children less than 5 years old with acute diarrhea in Kunming Children's Hospital. Clinical information and fecal specimens were collected and rotavirus were detected by polyacrylamide gel electrophoresis (PAGE) and/or enzyme linked immunosorbent assay (ELISA).

[Epidemiological study of rotavirus diarrhea in Beijing, China - a hospital-based surveillance from 1998 - 2001].

Objective: To provide information on epidemiology of rotavirus infection in Beijing, China.

Methods: An ongoing hospital-based surveillance was conducted among children < 5yr old with acute diarrhea according to WHO generic protocol (CID-98). During a 3-year study (Apr.

[Surveillance finding on rotavirus in Changchun children's hospital during July 1998-June 2001].

Objective: To establish baseline patterns of rotavirus diarrhea and to describe its epidemiologic features in Changchun city, prior to rotavirus vaccine immunization.

Methods: Hospital-based surveillance was conducted among children under 5 years old with acute diarrhea in Changchun Children's Hospital. Fecal samples were determined to identify rotavirus by PAGE and/or ELISA.

[Anticholera vaccines and vaccination].

Cholera is still an important diarrhoeal disease in developing countries. The impact of cholera out-break is tremendous for a country at human and economic level. WHO estimates that diarrhoeal diseases cause about 2.

Rotavirus strains circulating in Africa during 1996-1999: emergence of G9 strains and P[6] strains.

Rotavirus infection is associated with 150000-200000 deaths annually in Africa. Although the withdrawal of the RotaShield vaccine has been a major setback in rotavirus vaccine development, new vaccine candidates are under development and approaching phase II and III trials. Before these trials could be conducted in Africa, a comprehensive survey of the circulating VP7 serotypes and VP4 genotypes is required.

Diversity of rotavirus strains among children with acute diarrhea in China: 1998-2000 surveillance study.

As part of a national rotavirus surveillance activity, we collected fecal specimens from 3,177 children with acute diarrhea in 10 regions of China between April 1998 and April 2000 and screened them for rotavirus. Rotavirus was detected in 41% (n = 1,305) of specimens, and in these, G1 was the predominant serotype (72.6%), followed by G3 (14.

[Cholera update at the dawn of the millenium].

Cholera is an ancestral disease belonging to the mythology of numerous societies. In the last two centuries, seven pandemias have been recorded, in which the spatial and temporal modalities of disease transmission are related to the major technical revolutions of the period. The now ongoing seventh pandemia is by far the longest and most widespread with specific features that raise new challenges and hopes.

Investigations into the safety and immunogenicity of a killed oral cholera vaccine developed in Viet Nam.

Objective: To evaluate a killed oral cholera vaccine produced in Viet Nam, and to compare the Vietnamese vaccine with one that is licensed internationally.

Method: Two-dose regimens of a locally produced, bivalent, anti-O1, anti-O139 killed oral whole-cell cholera vaccine (biv-WC) and of a commercially available, monovalent (anti-O1) oral recombinant B subunit-killed whole-cell cholera vaccine (rBS-WC) were compared in two trials in Viet Nam. In the first trial, 144 adults were randomized to biv-WC with or without buffer, rBS-WC with buffer, or placebo without buffer.

A human volunteer challenge model using frozen bacteria of the new epidemic serotype, V. cholerae O139 in Thai volunteers.

A total of 35 volunteers were recruited for an IRB-approved inpatient dose-escalation challenge. The goal was to identify a dose that produced an observed cholera attack rate > or =80% and an illness of sufficient severity during the defined study period such that the model would be useful for determining vaccine protection. Volunteers were challenged in groups of 5 with V.

The WHO Vaccine Trial Registry.

The WHO Vaccine Trial Registry prospectively registers clinical vaccine studies supported by WHO. Through December 1999, the registry includes 103 studies from 43 countries, with nearly 80% in developing countries. The registry documents an expanding research capacity, with an average of 3.

Cost of immunization with a locally produced, oral cholera vaccine in Viet Nam.

Policy decisions regarding whether to incorporate new vaccines into routine public health practice in developing countries will depend in part on the costs of vaccine purchase and of vaccine delivery. In March, 1997, a large-scale effectiveness trial of a locally produced, orally administered bivalent vaccine against Vibrio cholerae 01 and 0139 began in Viet Nam. Empirical data obtained from the trial was used to determine the costs of the immunization campaign from the government perspective.